Ultrasound is frequently used in healthcare, for example in diagnosis and for monitoring pregnancies. Ultrasound is also used for detection of structural defects for example in machinery; and for other purposes. Ultrasound technology relies on detecting the scattering of sound waves. Sending and receiving the ultrasound wave is usually carried out with a piezoelectric transducer that can generate a sound wave upon receiving a voltage pulse and generate a voltage pulse upon receiving a sound wave.
Ultrasound probes consist of a plurality of piezoelectric crystals that each are controlled by a lead capable of sending and receiving voltage pulses. Ultrasound images are generated by transforming the voltage pulses that are generated by the transducers when they receive sound echoes caused by the previously sent ultrasound waves.
An ultrasound probe comprises several transducing elements. The number of transducing elements vary from 64 to 256, or even more.
Ultrasound probes need to be tested at regular intervals to ensure that they are working properly. Tests are carried out by specialized staff that are trained in ultrasound probe testing. Ultrasound probe testers regularly visit for example hospitals to test their ultrasound probes.
Problems with the probe may include problems with the leads, crosstalk between leads and errors in the transducers such as air under the lens, detachment of the backing material of the piezoelectric crystal, detachment of the piezoelectric crystal, and the transducers changing frequency.
Different instruments have been developed to cater to the business of ultrasounds probe testing.
The ultrasound test apparatus disclosed in U.S. Pat. No. 7,028,529 has one transmitter and one receiver and can test one lead and one transducing element at a time. Thus it has only one channel and usually interrogates the transducing elements one by one, which is a slow process. A relay matrix is used to switch the transmitter/receiver to the correct transducer. An advantage with relays according to U.S. Pat. No. 7,028,529 is to limit capacitive and resistive loads. However, relays are slow and it would be desirable to have a probe testing device with faster switching capabilities.